Daniel C. Postellon of the Helen DeVos Children’s Hospital, Michigan, writes in Nature’s Correspondence pages (Nature 452, 282; 2008):
The career of the non-existent author Ann Arbor is well-known to connoisseurs of computerized databases and citation indexes. Usually listed as the last author, she is sometimes credited with the academic degree “MI”. Ann is not actually a person, but the city of Ann Arbor, Michigan, home of the University of Michigan. Her ‘degree’ is a misinterpretation of the abbreviation for Michigan: MI. She pre-dates online computerized databases, and was often listed in the paper edition of Index Medicus.
Ms Arbor now has a UK rival in the team of Walton Hall and Milton Keynes. Like her, they are usually listed as last authors. The online database Google Scholar lists them as co-authors of 46 publications, in addition to their solo work. Walton Hall is actually a building on the campus of the Open University in Milton Keynes. These ‘authors’ have a useful role to play: they can be used to check the accuracy of the databases and indexes.